Direct evidence that PKCα positively regulates wound re-epithelialization: correlation with changes in desmosomal adhesiveness

J Pathol. 2012 Jul;227(3):346-56. doi: 10.1002/path.4016. Epub 2012 May 8.

Abstract

Non-healing wounds cause considerable patient morbidity and represent a significant economic burden. Central to wound repair is re-epithelialization, a crucial process involving the modulation of cell adhesion to allow keratinocyte migration to cover the exposed underlying tissues. The cellular mechanisms regulating the earliest stages of re-epithelialization are unclear. We present the first direct evidence that protein kinase Cα (PKCα) plays an important role in regulating wound re-epithelialization. In PKCα(-/-) mice re-epithelialization is delayed, while in novel bitransgenic mice over-expressing constitutively active PKCα it is accelerated. These effects are not due to changes in keratinocyte proliferation, apoptosis or intrinsic cell motility. Instead, they correlate with changes in desmosomal adhesiveness, delay being preceded by retained desmosomal hyper-adhesiveness and acceleration with a rapid switch to desmosomal Ca(2+) -dependence. We demonstrate mechanistic conservation in acute human wounds where PKCα localizes to wound edge desmosomes, which become Ca(2+) -dependent. However, in chronic wounds PKCα remains cytoplasmic and desmosomes fail to switch from the hyper-adhesive state. These results throw new mechanistic light on the earliest stages of wound re-epithelialization and suggest activation of PKCα as a new therapeutic strategy for non-healing wounds.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Calcium / metabolism
  • Cell Adhesion* / drug effects
  • Cell Line
  • Cell Movement
  • Cell Proliferation
  • Desmosomes / drug effects
  • Desmosomes / enzymology*
  • Desmosomes / pathology
  • Dose-Response Relationship, Drug
  • Enzyme Activation
  • Genotype
  • Humans
  • Keratinocytes / drug effects
  • Keratinocytes / enzymology*
  • Keratinocytes / pathology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mice, Transgenic
  • Phenotype
  • Point Mutation
  • Protein Kinase C-alpha / antagonists & inhibitors
  • Protein Kinase C-alpha / deficiency
  • Protein Kinase C-alpha / genetics
  • Protein Kinase C-alpha / metabolism*
  • Protein Kinase Inhibitors / pharmacology
  • Signal Transduction
  • Time Factors
  • Wound Healing* / drug effects

Substances

  • Protein Kinase Inhibitors
  • PRKCA protein, human
  • Prkca protein, mouse
  • Protein Kinase C-alpha
  • Calcium